In vitro orthodontic bracket bonding to porcelain

Abstract

This in vitro study investigated the influence of using different combinations of bracket, adhesive, and light-curing source on the tensile bond strength to porcelain and on failure patterns at debonding. Tensile tests were performed using: one ceramic bracket versus one metal bracket, two orthodontic composites; type bisphenol A-glycidyldimethacrylate and urethane dimethacrylate (UDMA), and four light-curing units with the same range of emission spectrum but various light intensities: three light-emitting diode (LED) units and one halogen-based unit. One hundred and sixty porcelain samples were randomly divided into 16 equal groups. The porcelain surface was conditioned with 9 per cent hydrofluoric acid before silane application. The composite was photo-polymerized for 40 seconds. After storage in water at 37°C for 24 hours, the samples were subjected to tensile force until bond failure. Bond strength and bond failure mode were recorded; results were analysed (α = 0.05) using R language; linear model with constant variance for the bond strength and multinomial distribution for the failure mode. The bond strength in all groups was sufficient to withstand orthodontic treatment (>6 MPa). There was no statistical difference between the adhesives, but comparing bracket × light interaction, it was significantly higher with the ceramic bracket. No significant differences were seen between the metal bracket groups, but for the ceramic bracket, the results were significantly higher with the LED light. No fracture was observed in porcelain with the metal bracket but it occurred in 35 per cent of the ceramic bracket samples and the risk was higher when using UDMA composite and lower with LED high intensity light.

Influence of Light Source, Thermocycling and Silane on the Shear Bond Strength of Metallic Brackets to Ceramic

“…The results showed that significant differences were observed between LED and QTH regardless of the thermocycling and silane condition. These results are in line with those of previous studies, which also found significant differences between QTH and LED units (8)(9)(10). Other study showed that photo-activation is dependent on the radiant exposure (16).…”

Orthodontic bonding to porcelain: A systematic review

“…1,2 This has encouraged orthodontists to test several different protocols with respect to bonding brackets to different dental restorations (specifically porcelain/ceramic restorations). Bonding orthodontic brackets to porcelain/ceramic surfaces presents a higher degree of failure when compared to bonding to enamel.…”

“…Many times this is granted to the porcelain type and surface conditioning, bracket material (base design, retention mode), properties of the bonding adhesive, and the light-curing source, as well as the skill of the clinician. 2,3 Also, adequate bond strength is desired with easy removal to avoid damage of the restored teeth. 4,5 Several techniques have been used to bond brackets to porcelain surfaces and these differ in surface preparation and bonding agent applied.…”

Influence of different orthodontic brackets and chemical preparations of ceramic crowns on shear bond strength

“…Obtaining sufficient bond strength is difficult when using only mechanical conditioning procedures with diamond stone burs, sandblasting, or sandpaper discs, and all these procedures damage the glazed surface of the ceramic restoration. [4][5][6][7][8][9][10][11] A combination of acids and silane coupling agent is recommended for chemical preparation of the glazed ceramic surface before bonding. [12][13][14] Silane enhances bond strength by increasing the chemical bond between the resin composite and the ceramic material.…”